BRUSSELS, March 13. /TASS/. Six NATO war ships have called at Romania's Black Sea port of Constanta as part of military drills, the press service of the North Atlantic Alliance reported Friday.

The six NATO vessels have been in the Black Sea since March 4 on invitation from Romania, Bulgaria and Turkey for planned maneuvers. The group includes USS Vicksburg, four frigates - Turkey's Turgut Reis, Italy's Aliseo, Canada's Fredericton and Romania's Regina Maria, as well as Germany's Spessart auxiliary ship. US Vice-Admiral Brad Williamson is in charge of the group.

According to NATO’s press-service the drills are aimed at practising protection from air raids and from torpedo attacks by submarines.

NATO warships are obliged to meet the conditions of the Monroe doctrine not to stay in the Black Sea basin longer than 21 days. The water displacement of NATO warships staying in the Black Sea should not exceed 45,000 tons.

NATO fears Crimea’s increased defense capability

The four-star US General Philip Breedlove, NATO Supreme Allied Commander Europe, is concerned with Russian efforts to strengthen the defense capability of Russia’s Crimean peninsula. At his recent meeting with journalists, General Breedlove said that NATO had noticed significant changes in the deployment of weapons in Crimea. Russian anti-aircraft systems are controlling approximately half of the Black Sea while "surface to surface" missiles are covering its area completely. These anti-aircraft systems, Breedlove said, have turned Crimea into a strong bridgehead ensuring the projection of force in the region.

Russian Defense Minister Sergey Shoigu has openly said that the aggravation of the Ukraine crisis and growing foreign military presence off Russian borders have impelled Russia to introduce some changes in the work of the command of the Southern Military District, which comprises Crimea. That is why the deployment of a full-fledged and self-sufficient group of troops in the Crimean direction has become a priority task for the Russian military leadership.